RESUMO
BACKGROUND: Acute cannabis administration can produce transient psychotic-like effects in healthy individuals. However, the mechanisms through which this occurs and which factors predict vulnerability remain unclear. We investigate whether cannabis inhalation leads to psychotic-like symptoms and speech illusion; and whether cannabidiol (CBD) blunts such effects (study 1) and adolescence heightens such effects (study 2). METHODS: Two double-blind placebo-controlled studies, assessing speech illusion in a white noise task, and psychotic-like symptoms on the Psychotomimetic States Inventory (PSI). Study 1 compared effects of Cann-CBD (cannabis containing Δ-9-tetrahydrocannabinol (THC) and negligible levels of CBD) with Cann+CBD (cannabis containing THC and CBD) in 17 adults. Study 2 compared effects of Cann-CBD in 20 adolescents and 20 adults. All participants were healthy individuals who currently used cannabis. RESULTS: In study 1, relative to placebo, both Cann-CBD and Cann+CBD increased PSI scores but not speech illusion. No differences between Cann-CBD and Cann+CBD emerged. In study 2, relative to placebo, Cann-CBD increased PSI scores and incidence of speech illusion, with the odds of experiencing speech illusion 3.1 (95% CIs 1.3-7.2) times higher after Cann-CBD. No age group differences were found for speech illusion, but adults showed heightened effects on the PSI. CONCLUSIONS: Inhalation of cannabis reliably increases psychotic-like symptoms in healthy cannabis users and may increase the incidence of speech illusion. CBD did not influence psychotic-like effects of cannabis. Adolescents may be less vulnerable to acute psychotic-like effects of cannabis than adults.
Assuntos
Canabidiol , Cannabis , Alucinógenos , Ilusões , Adulto , Adolescente , Humanos , Canabidiol/efeitos adversos , Dronabinol/efeitos adversos , Alucinógenos/farmacologia , Agonistas de Receptores de CanabinoidesRESUMO
Understanding genetic factors that contribute to cannabis use disorder (CUD) is important, but to date, findings have been equivocal. Single-nucleotide polymorphisms (SNPs) in the cannabinoid receptor 1 gene (CNR1; rs1049353 and rs806378) and fatty acid amide hydrolase (FAAH) gene (rs324420) have been implicated in CUD. Their relationship to addiction endophenotypes such as cannabis-related state satiety, the salience of appetitive cues, and craving after acute cannabinoid administration has not been investigated. Forty-eight cannabis users participated in a double-blind, placebo-controlled, four-way crossover experiment where they were administered treatments in a randomized order via vaporization: placebo, Δ9 -tetrahydrocannabinol (THC) (8 mg), THC + cannabidiol (THC + CBD) (8 + 16 mg), and CBD (16 mg). Cannabis-related state satiety, appetitive cue salience (cannabis and food), and cannabis craving were assessed each day. Participants were genotyped for rs1049353, rs806378, and rs324420. Results indicated that CNR1 rs1049353 GG carriers showed increased state satiety after THC/THC + CBD administration in comparison with placebo and reduced the salience of appetitive cues after THC in comparison with CBD administration; A carriers did not vary on either of these measures indicative of a vulnerability to CUD. CNR1 rs806378 CC carriers showed greater salience to appetitive cues in comparison with T carriers, but there was no evidence for changes in state satiety. FAAH rs324420 A carriers showed greater bias to appetitive cues after THC, in comparison with CC carriers. FAAH CC carriers showed reduced bias after THC in comparison with CBD. No SNPs modulated craving. These findings identify candidate neurocognitive mechanisms through which endocannabinoid system genetics may influence vulnerability to CUD.
Assuntos
Amidoidrolases/genética , Canabidiol/farmacologia , Agonistas de Receptores de Canabinoides/farmacologia , Fissura/fisiologia , Dronabinol/farmacologia , Abuso de Maconha/genética , Receptor CB1 de Canabinoide/genética , Saciação/fisiologia , Adolescente , Fissura/efeitos dos fármacos , Estudos Cross-Over , Sinais (Psicologia) , Método Duplo-Cego , Endofenótipos , Feminino , Humanos , Masculino , Abuso de Maconha/fisiopatologia , Saciação/efeitos dos fármacos , Adulto JovemRESUMO
BACKGROUND: Changes in cannabis regulation globally make it increasingly important to determine what predicts an individual's risk of experiencing adverse drug effects. Relevant studies have used diverse self-report measures of cannabis use, and few include multiple biological measures. Here we aimed to determine which biological and self-report measures of cannabis use predict cannabis dependency and acute psychotic-like symptoms. METHOD: In a naturalistic study, 410 young cannabis users were assessed once when intoxicated with their own cannabis and once when drug-free in counterbalanced order. Biological measures of cannabinoids [(Δ9-tetrahydrocannabinol (THC), cannabidiol (CBD), cannabinol (CBN) and their metabolites)] were derived from three samples: each participant's own cannabis (THC, CBD), a sample of their hair (THC, THC-OH, THC-COOH, CBN, CBD) and their urine (THC-COOH/creatinine). Comprehensive self-report measures were also obtained. Self-reported and clinician-rated assessments were taken for cannabis dependency [Severity of Dependence Scale (SDS), DSM-IV-TR] and acute psychotic-like symptoms [Psychotomimetic State Inventory (PSI) and Brief Psychiatric Rating Scale (BPRS)]. RESULTS: Cannabis dependency was positively associated with days per month of cannabis use on both measures, and with urinary THC-COOH/creatinine for the SDS. Acute psychotic-like symptoms were positively associated with age of first cannabis use and negatively with urinary THC-COOH/creatinine; no predictors emerged for BPRS. CONCLUSIONS: Levels of THC exposure are positively associated with both cannabis dependency and tolerance to the acute psychotic-like effects of cannabis. Combining urinary and self-report assessments (use frequency; age first used) enhances the measurement of cannabis use and its association with adverse outcomes.
Assuntos
Canabinoides/metabolismo , Abuso de Maconha/diagnóstico , Uso da Maconha/efeitos adversos , Psicoses Induzidas por Substâncias/diagnóstico , Autorrelato , Adolescente , Adulto , Fatores Etários , Canabinoides/urina , Feminino , Cabelo/química , Humanos , Masculino , Abuso de Maconha/metabolismo , Uso da Maconha/metabolismo , Prognóstico , Psicoses Induzidas por Substâncias/metabolismo , Fatores de Tempo , Urinálise , Adulto JovemRESUMO
Background: Despite the current shift towards permissive cannabis policies, few studies have investigated the pleasurable effects users seek. Here, we investigate the effects of cannabis on listening to music, a rewarding activity that frequently occurs in the context of recreational cannabis use. We additionally tested how these effects are influenced by cannabidiol, which may offset cannabis-related harms. Methods: Across 3 sessions, 16 cannabis users inhaled cannabis with cannabidiol, cannabis without cannabidiol, and placebo. We compared their response to music relative to control excerpts of scrambled sound during functional Magnetic Resonance Imaging within regions identified in a meta-analysis of music-evoked reward and emotion. All results were False Discovery Rate corrected (P<.05). Results: Compared with placebo, cannabis without cannabidiol dampened response to music in bilateral auditory cortex (right: P=.005, left: P=.008), right hippocampus/parahippocampal gyrus (P=.025), right amygdala (P=.025), and right ventral striatum (P=.033). Across all sessions, the effects of music in this ventral striatal region correlated with pleasure ratings (P=.002) and increased functional connectivity with auditory cortex (right: P< .001, left: P< .001), supporting its involvement in music reward. Functional connectivity between right ventral striatum and auditory cortex was increased by cannabidiol (right: P=.003, left: P=.030), and cannabis with cannabidiol did not differ from placebo on any functional Magnetic Resonance Imaging measures. Both types of cannabis increased ratings of wanting to listen to music (P<.002) and enhanced sound perception (P<.001). Conclusions: Cannabis dampens the effects of music in brain regions sensitive to reward and emotion. These effects were offset by a key cannabis constituent, cannabidol.
Assuntos
Mapeamento Encefálico , Encéfalo/efeitos dos fármacos , Canabidiol/farmacologia , Emoções/efeitos dos fármacos , Música , Recompensa , Estimulação Acústica , Adulto , Pressão Sanguínea/efeitos dos fármacos , Encéfalo/diagnóstico por imagem , Cannabis/metabolismo , Estudos Cross-Over , Método Duplo-Cego , Feminino , Frequência Cardíaca/efeitos dos fármacos , Humanos , Processamento de Imagem Assistida por Computador , Masculino , Fumar Maconha/fisiopatologia , Oxigênio/sangue , Adulto JovemRESUMO
BACKGROUND: Use of cannabis-based products is becoming more frequent, and it is important that healthcare professionals are informed and confident about them when making evidence-based decisions about their use. This study aimed to gain an international perspective on the attitudes, knowledge, and confidence of healthcare professionals about cannabis-based products. METHODS: An online questionnaire regarding these products was completed by 1580 healthcare professionals (neurologists, psychiatrists, general practitioners, pharmacists and nurses) from 16 countries across Asia, Europe, Oceania, South America, and the Middle East. RESULTS: Respondents expressed a high level of interest in cannabis-based products (median score 9 out of 10) and reported that they felt knowledgeable about them (median score 6 out of 7). They reported a high level of confidence when providing patients with information on cannabis-based products, returning median scores of 6 and 5 out of 7 for their legality and regulations, and their benefits and risks, respectively. Despite this, healthcare professionals sought further information on cannabis-based products across areas including legality, neurobiology, and scientific evidence. Finally, 59% (n = 930) of respondents considered robust clinical trial evidence as the most important factor to ensure patient safety in the context of these products. Few nominally significant differences emerged between healthcare professionals from different specialities or regions. CONCLUSION: In conclusion, this large survey of attitudes held by healthcare professionals towards cannabis-based products revealed a high level of interest and a demand for more information. Limitations of this study include potential sample bias and limited external validity.
RESUMO
OBJECTIVES: Lung cancer (LC) continues to be the leading cause of cancer-related deaths and while there have been significant improvements in overall survival, this gain is not equally distributed. To address health inequalities (HIs), it is vital to identify whether and where they exist. This paper reviews existing literature on what HIs impact LC care and where these manifest on the care pathway. DESIGN: A systematic scoping review based on Arksey and O'Malley's five-stage framework. DATA SOURCES: Multiple databases (EMBASE, HMIC, Medline, PsycINFO, PubMed) were used to retrieve articles. ELIGIBILITY CRITERIA: Search limits were set to retrieve articles published between January 2012 and April 2022. Papers examining LC along with domains of HI were included. Two authors screened papers and independently assessed full texts. DATA EXTRACTION AND SYNTHESIS: HIs were categorised according to: (a) HI domains: Protected Characteristics (PC); Socioeconomic and Deprivation Factors (SDF); Geographical Region (GR); Vulnerable or Socially Excluded Groups (VSG); and (b) where on the LC pathway (access to, outcomes from, experience of care) inequalities manifest. Data were extracted by two authors and collated in a spreadsheet for structured analysis and interpretation. RESULTS: 41 papers were included. The most studied domain was PC (32/41), followed by SDF (19/41), GR (18/41) and VSG (13/41). Most studies investigated differences in access (31/41) or outcomes (27/41), with few (4/41) exploring experience inequalities. Evidence showed race, rural residence and being part of a VSG impacted the access to LC diagnosis, treatment and supportive care. Additionally, rural residence, older age or male sex negatively impacted survival and mortality. The relationship between outcomes and other factors (eg, race, deprivation) showed mixed results. CONCLUSIONS: Findings offer an opportunity to reflect on the understanding of HIs in LC care and provide a platform to consider targeted efforts to improve equity of access, outcomes and experience for patients.
Assuntos
Neoplasias Pulmonares , Humanos , Masculino , Neoplasias Pulmonares/terapia , Atenção à SaúdeRESUMO
INTRODUCTION: Increasing cannabis legalization raises concerns that the use of tobacco, frequently used with cannabis, will also increase. This study investigated the association between the legal status of cannabis in places of residence and the prevalence of cannabis and tobacco co-use, simultaneous use, and mixing by comparing the prevalence among adults in Canada (prior to cannabis legalization) vs. adults in US states that had legalized recreational cannabis vs. US states that had not as of September 2018. METHODS: Data were drawn from the 2018 International Cannabis Policy Study, conducted with respondents aged 16-65 in Canada and the US recruited from nonprobability consumer panels. Differences in the prevalence of co-use, simultaneous use, and mixing between tobacco and different cannabis products were examined using logistic regression models by legal status of place of residence among past-12-month cannabis consumers (N = 6744). RESULTS: Co-use and simultaneous use in the past 12 months were most common among respondents in US legal states. Among cannabis consumers, co-use and simultaneous use were less common in US legal states, while mixing was less frequent in US states with both legal and illegal cannabis compared to Canada. Use of edibles was associated with lower odds of all three outcomes, while smoking dried herb or hash was associated with higher odds. CONCLUSIONS: The proportion of cannabis consumers who used tobacco was lower in legal jurisdictions despite higher prevalence of cannabis use. Edible use was inversely associated with co-use, suggesting that edible use does not appear to be associated with increased tobacco use.
Assuntos
Cannabis , Fumar/epidemiologia , Canadá/epidemiologia , Uso de Tabaco/epidemiologiaRESUMO
Cannabidiol (CBD) has shown promise in treating psychiatric disorders, including cannabis use disorder - a major public health burden with no approved pharmacotherapies. However, the mechanisms through which CBD acts are poorly understood. One potential mechanism of CBD is increasing levels of anandamide, which has been implicated in psychiatric disorders including depression and cannabis use disorder. However, there is a lack of placebo-controlled human trials investigating this in psychiatric disorders. We therefore assessed whether CBD affects plasma anandamide levels compared to placebo, within a randomised clinical trial of CBD for the treatment of cannabis use disorder. Individuals meeting criteria for cannabis use disorder and attempting cannabis cessation were randomised to 28-day administration with placebo (n = 23), 400 mg CBD/day (n = 24) or 800 mg CBD/day (n = 23). We estimated the effects of each CBD dose compared to placebo on anandamide levels from baseline to day 28. Analyses were conducted both unadjusted and adjusted for cannabis use during the trial to account for effects of cannabis on the endocannabinoid system. We also investigated whether changes in plasma anandamide levels were associated with clinical outcomes relevant for cannabis use disorder (cannabis use, withdrawal, anxiety, depression). There was an effect of 800 mg CBD compared to placebo on anandamide levels from baseline to day 28 after adjusting for cannabis use. Pairwise comparisons indicated that anandamide levels unexpectedly reduced from baseline to day 28 in the placebo group (-0.048, 95% CI [-0.089, -0.007]), but did not change in the 800 mg CBD group (0.005, 95% CI [-0.036, 0.047]). There was no evidence for an effect of 400 mg CBD compared to placebo. Changes in anandamide levels were not associated with clinical outcomes. In conclusion, this study found preliminary evidence that 28-day treatment with CBD modulates anandamide levels in individuals with cannabis use disorder at doses of 800 mg/day but not 400 mg/day compared to placebo.
Assuntos
Canabidiol , Cannabis , Alucinógenos , Abuso de Maconha , Humanos , Canabidiol/uso terapêutico , Canabidiol/farmacologia , Endocanabinoides , Abuso de Maconha/tratamento farmacológico , Dronabinol/farmacologia , Método Duplo-CegoRESUMO
RATIONALE: Chronic cannabis use is associated with impaired cognitive function. Evidence indicates cannabidiol (CBD) might be beneficial for treating cannabis use disorder. CBD may also have pro-cognitive effects; however, its effect on cognition in people with cannabis use disorder is currently unclear. OBJECTIVES: We aimed to assess whether a 4-week CBD treatment impacted cognitive function. We hypothesised that CBD treatment would improve cognition from baseline to week 4, compared to placebo. METHODS: Cognition was assessed as a secondary outcome in a phase 2a randomised, double-blind, parallel-group and placebo-controlled clinical trial of 4-week daily 200 mg, 400 mg and 800 mg CBD for the treatment of cannabis use disorder. Participants had moderate or severe DSM-5 cannabis use disorder and intended to quit cannabis use. Our pre-registered primary cognitive outcome was delayed prose recall. Secondary cognitive outcomes were immediate prose recall, stop signal reaction time, trail-making task performance, verbal fluency and digit span. RESULTS: Seventy participants were randomly assigned to placebo (n = 23), 400 mg CBD (n = 24) and 800 mg CBD (n = 23). A 200 mg group was eliminated from the trial because it was an inefficacious dose at interim analysis (n = 12) and was not analysed here. For the primary cognitive outcome, there was no effect of CBD compared to placebo, evidenced by a lack of dose-by-time interaction at 400 mg (0.46, 95%CIs: - 1.41, 2.54) and 800 mg (0.89, 95%CIs: - 0.99, 2.81). There was no effect of CBD compared to placebo on secondary cognitive outcomes, except backwards digit span which increased following 800 mg CBD (0.30, 95%CIs: 0.02, 0.58). CONCLUSIONS: In this clinical trial for cannabis use disorder, CBD did not influence delayed verbal memory. CBD did not have broad cognitive effects but 800 mg daily treatment may improve working memory manipulation. CLINICAL TRIAL REGISTRATION: The trial was registered with ClinicalTrials.gov (NCT02044809) and the EU Clinical Trials Register (2013-000,361-36).
Assuntos
Canabidiol , Cannabis , Alucinógenos , Abuso de Maconha , Transtornos Relacionados ao Uso de Substâncias , Humanos , Canabidiol/farmacologia , Canabidiol/uso terapêutico , Abuso de Maconha/complicações , Abuso de Maconha/tratamento farmacológico , Alucinógenos/farmacologia , Transtornos Relacionados ao Uso de Substâncias/tratamento farmacológico , Cannabis/efeitos adversos , Cognição , Método Duplo-CegoRESUMO
RATIONALE: There is growing interest in the therapeutic potential of cannabidiol (CBD) across a range of psychiatric disorders. CBD has been found to reduce anxiety during experimentally induced stress in anxious individuals and healthy controls. However, the mechanisms underlying the putative anxiolytic effects of CBD are unknown. OBJECTIVES: We sought to investigate the behavioural and neural effects of a single dose of CBD vs. placebo on a range of emotion-related measures to test cognitive-mechanistic models of its effects on anxiety. METHODS: We conducted a randomised, double-blind, placebo-controlled, crossover, acute oral challenge of 600 mg of CBD in 24 healthy participants on emotional processing, with neuroimaging (viewing emotional faces during functional magnetic resonance imaging) and cognitive (emotional appraisal) measures as well as subjective response to experimentally induced anxiety. RESULTS: CBD did not produce effects on brain responses to emotional faces and cognitive measures of emotional processing, or modulate experimentally induced anxiety, relative to placebo. CONCLUSIONS: Given the rising popularity of CBD for its putative medical benefits, these findings question whether further research is warranted to investigate the clinical potential of CBD for the treatment of anxiety disorders.
Assuntos
Ansiolíticos , Canabidiol , Ansiolíticos/farmacologia , Ansiedade/psicologia , Transtornos de Ansiedade/tratamento farmacológico , Método Duplo-Cego , Emoções , HumanosRESUMO
BACKGROUND: Cannabidiol (CBD) and Δ9-tetrahydrocannabinol (THC) are the two major constituents of cannabis with contrasting mechanisms of action. THC is the major psychoactive, addiction-promoting, and psychotomimetic compound, while CBD may have opposite effects. The brain effects of these drugs alone and in combination are poorly understood. In particular, the striatum is implicated in the pathophysiology of several psychiatric disorders, but it is unclear how THC and CBD influence striato-cortical connectivity. AIMS: To examine effects of THC, CBD, and THC + CBD on functional connectivity of striatal sub-divisions (associative, limbic and sensorimotor). METHOD: Resting-state functional Magnetic Resonance Imaging (fMRI) was used across two within-subjects, placebo-controlled, double-blind studies, with a unified analysis approach. RESULTS: Study 1 (N = 17; inhaled cannabis containing 8 mg THC, 8 mg THC + 10 mg CBD or placebo) showed strong disruptive effects of both THC and THC + CBD on connectivity in the associative and sensorimotor networks, but a specific effect of THC in the limbic striatum network which was not present in the THC + CBD condition. In Study 2 (N = 23, oral 600 mg CBD, placebo), CBD increased connectivity in the associative network, but produced only relatively minor disruptions in the limbic and sensorimotor networks. OUTCOMES: THC strongly disrupts striato-cortical networks, but this effect is mitigated by co-administration of CBD in the limbic striatum network. Oral CBD administered has a more complex effect profile of relative increases and decreases in connectivity. The insula emerges as a key region affected by cannabinoid-induced changes in functional connectivity, with potential implications for understanding cannabis-related disorders, and the development of cannabinoid therapeutics.
Assuntos
Canabidiol , Canabinoides , Cannabis , Alucinógenos , Encéfalo , Canabidiol/farmacologia , Agonistas de Receptores de Canabinoides/farmacologia , Canabinoides/farmacologia , Método Duplo-Cego , Dronabinol/farmacologia , Alucinógenos/farmacologia , HumanosRESUMO
BACKGROUND: The lack of an agreed international minimum approach to measuring cannabis use hinders the integration of multidisciplinary evidence on the psychosocial, neurocognitive, clinical and public health consequences of cannabis use. METHODS: A group of 25 international expert cannabis researchers convened to discuss a multidisciplinary framework for minimum standards to measure cannabis use globally in diverse settings. RESULTS: The expert-based consensus agreed upon a three-layered hierarchical framework. Each layer-universal measures, detailed self-report and biological measures-reflected different research priorities and minimum standards, costs and ease of implementation. Additional work is needed to develop valid and precise assessments. CONCLUSIONS: Consistent use of the proposed framework across research, public health, clinical practice and medical settings would facilitate harmonisation of international evidence on cannabis consumption, related harms and approaches to their mitigation.
Assuntos
Cannabis , Consenso , Custos e Análise de Custo , Humanos , AutorrelatoRESUMO
BACKGROUND: Nationally representative data of cannabis-tobacco co-use have shown that these substances are closely entwined and have significant adverse health consequences, although population-level harms of co-use are largely unknown. Current epidemiological research does not assess co-use in a manner that has yielded the necessary data to draw conclusions regarding health effects. This has given rise to a hidden population of co-users who go under-served. Therefore, this paper has two aims: (1) to review new challenges in the collection of co-use data due to rapidly changing regulations of cannabis and nicotine products and (2) to provide recommendations for the terminology and assessment of co-use. ARGUMENT: We argue that: (1) the prevalence of co-use is not being assessed accurately at a population level and (2) changes in legalization have created novel challenges, but without proper monitoring the impact on co-use will go undetected. We propose a three-level tiered set of recommendations for co-use assessments, which includes assessments of cannabis, tobacco and co-use metrics ranging from least burdensome (self-report of co-administered products) to most burdensome (assays, event-level data). CONCLUSIONS: We propose that clinical studies begin to incorporate cannabis-tobacco co-use assessments to justify better their inclusion in clinical trials and national surveillance surveys. Integration of co-use assessments will aid in understanding the true impact on co-use of the changing cannabis and tobacco/nicotine regulatory environments. Co-use is prevalent and problematic, and the ability to make conclusions about its health outcomes is hindered by lack of nuance in data collection. If you do not measure it, you cannot manage it.
Assuntos
Cannabis , Fumar Maconha , Produtos do Tabaco , Humanos , Fumar Maconha/epidemiologia , Nicotiana , Uso de TabacoRESUMO
BACKGROUND: Public and medical interest in cannabidiol (CBD) has been rising, and CBD is now available from various sources. Research into the effects of low-dose CBD on outcomes like stress, anxiety, and sleep problems have been scarce, so we conducted an online survey of CBD users to better understand patterns of use, dose, and self-perceived effects of CBD. METHODS: The sample consisted of 387 current or past-CBD users who answered a 20-question online survey. The survey was sent out to CBD users through email databases and social media. Participants reported basic demographics, CBD use patterns, reasons for use, and effects on anxiety, sleep, and stress. RESULTS: The sample (N = 387) consisted of 61.2% females, mostly between 25 and 54 years old (72.2%) and primarily based in the UK (77.4%). The top 4 reasons for using CBD were self-perceived anxiety (42.6%), sleep problems (42.5%), stress (37%), and general health and wellbeing (37%). Fifty-four per cent reported using less than 50 mg CBD daily, and 72.6% used CBD sublingually. Adjusted logistic models show females had lower odds than males of using CBD for general health and wellbeing [OR 0.45, 95% CI 0.30-0.72] and post-workout muscle-soreness [OR 0.46, 95%CI 0.24-0.91] but had higher odds of using CBD for self-perceived anxiety [OR 1.60, 95% CI 0.02-2.49] and insomnia [OR 1.87, 95% CI 1.13-3.11]. Older individuals had lower odds of using CBD for general health and wellbeing, stress, post-workout sore muscles, anxiety, skin conditions, focusing, and sleep but had higher odds of using CBD for pain. Respondents reported that CBD use was effective for stress, sleep problems, and anxiety in those who used the drug for those conditions. CONCLUSION: This survey indicated that CBD users take the drug to manage self-perceived anxiety, stress, sleep, and other symptoms, often in low doses, and these patterns vary by demographic characteristics. Further research is required to understand how low doses, representative of the general user, might impact mental health symptoms like stress, anxiety, and sleep problems.
RESUMO
BACKGROUND AND AIMS: In Great Britain, cannabis and tobacco are commonly used substances, both independently and together. Use of either substance is associated with mental health problems, but prevalence of co-use within these populations is unknown. We aimed to (1) estimate prevalence of cannabis use, frequency of use and routes of administration (ROA) among tobacco smokers and non-smokers and (2) investigate mental health problems among non-users, tobacco-only, cannabis-only and co-users of both substances. DESIGN: Cross-sectional national on-line survey (Action on Smoking and Health) fielded in February-March 2020. SETTING: Great Britain. PARTICIPANTS: Adults in Great Britain aged ≥ 18 years (n = 12 809) MEASUREMENTS: Tobacco use status [smoker (daily or non-daily) or non-smoker (never or ex-smoker)], cannabis use frequency (never to daily), detailed ROAs of cannabis, self-reported treatment for mental health disorders (depression, anxiety and any). Statistically weighted prevalence estimates were computed to ensure representativeness. Correlates were assessed using χ2 tests and logistic regression. FINDINGS: In Great Britain in 2020, 7.1% of the sample had used cannabis in the past year. Tobacco smokers had greater odds of using cannabis in the past year (21.9%) and using cannabis daily (8.7%) than non-smokers [past-year: 4.7%; adjusted odds ratio (aOR) = 10.07, 95% confidence interval (CI) = 8.4-12.0; daily: 0.7%; aOR = 24.6, 95% CI = 18.0-33.6)]. Co-administration with tobacco was common (46.2% of non-smokers, 80.8% of tobacco smokers). Co-users reported the highest prevalence of any treatment for mental health problems (54.2%) in comparison to cannabis-only (45.8%), tobacco-only (33.2%) and non-users (22.7%; all P ≤ 0.05). CONCLUSION: Approximately one in 13 adults in Great Britain reports having used cannabis in the past year, approximately four times as many among cigarette smokers as non-smokers. Co-administration of cannabis and tobacco, via smoking, appears to be common, including among self-identified non-smokers. Mental health problems appear to be particularly common among dual users.
Assuntos
Cannabis , Fumar Maconha , Adulto , Estudos Transversais , Humanos , Fumar Maconha/epidemiologia , Saúde Mental , não Fumantes , Prevalência , Fumantes , Reino Unido/epidemiologiaRESUMO
Cannabis has been legalised for medical use in an ever-increasing number of countries. A growing body of scientific evidence supports the use of medical cannabis for a range of therapeutic indications. In parallel with these developments, concerns have been expressed by many prescribers that increased use will lead to patients developing cannabis use disorder. Cannabis use disorder has been widely studied in recreational users, and these findings have often been projected onto patients using medical cannabis. However, studies exploring medical cannabis dependence are scarce and the appropriate methodology to measure this construct is uncertain. This article provides a narrative review of the current research to discern if, how and to what extent, concerns about problems of dependence in recreational cannabis users apply to prescribed medical users. We focus on the main issues related to medical cannabis and dependence, including the importance of dose, potency, cannabinoid content, pharmacokinetics and route of administration, frequency of use, as well as set and setting. Medical and recreational cannabis use differs in significant ways, highlighting the challenges of extrapolating findings from the recreational cannabis literature. There are many questions about the potential for medical cannabis use to lead to dependence. It is therefore imperative to address these questions in order to be able to minimise harms of medical cannabis use. We draw out seven recommendations for increasing the safety of medical cannabis prescribing. We hope that the present review contributes to answering some of the key questions surrounding medical cannabis dependence.
Assuntos
Moduladores de Receptores de Canabinoides/farmacologia , Abuso de Maconha/etiologia , Maconha Medicinal/farmacologia , Moduladores de Receptores de Canabinoides/administração & dosagem , Moduladores de Receptores de Canabinoides/efeitos adversos , Humanos , Maconha Medicinal/administração & dosagem , Maconha Medicinal/efeitos adversosRESUMO
BACKGROUND: Mindfulness-meditation has a variety of benefits on well-being. However, individuals with primary attentional impairments (e.g. attention deficit disorder) or attentional symptoms secondary to anxiety, depression or addiction, may be less likely to benefit, and require additional mindfulness-augmenting strategies. AIMS: To determine whether a single dose of the cognitive enhancer, modafinil, acutely increases subjective and behavioural indices of mindfulness, and augments brief mindfulness training. METHODS: A randomised, double-blind, placebo-controlled, 2 (drug: placebo, modafinil) × 2 (strategy: mindfulness, relaxation control) experiment was conducted. Seventy-nine meditation-naïve participants were assigned to: placebo-relaxation, placebo-mindfulness, modafinil-relaxation or modafinil-mindfulness. Pre-drug, post-drug and post-strategy state mindfulness, affect and autonomic activity, along with post-strategy sustained attention and mind-wandering were assessed within a single lab session. After the session, participants were instructed to practice their assigned behavioural strategy daily for one week, with no further drug administration, after which, follow-up measures were taken. RESULTS: As predicted, modafinil acutely increased state mindfulness and improved sustained attention. Differential acute strategy effects were found following mindfulness on autonomic activity but not state mindfulness. There were no strategy or drug effects on mind-wandering. However, exploratory analyses indicated that participants receiving modafinil engaged in more strategy practice across strategy conditions during follow-up. CONCLUSIONS: Modafinil acutely mimicked the effects of brief mindfulness training on state mindfulness but did not enhance the effects of this training. Limitations of the current study, and recommendations for future research examining modafinil as an adjunct to mindfulness- (or relaxation-) based treatments are discussed.
Assuntos
Meditação/métodos , Atenção Plena/métodos , Modafinila/administração & dosagem , Nootrópicos/administração & dosagem , Adolescente , Adulto , Atenção/efeitos dos fármacos , Transtorno do Deficit de Atenção com Hiperatividade/terapia , Terapia Combinada , Método Duplo-Cego , Feminino , Seguimentos , Humanos , Masculino , Modafinila/farmacologia , Nootrópicos/farmacologia , Adulto JovemRESUMO
BACKGROUND: While the acute effects of cannabis are relatively benign for most users, some individuals experience significant adverse effects. This study aimed to identify whether variation in schizotypal personality traits and frequency of cannabis use influence the acute effects of delta-9-tetrahydrocannabinol (THC). METHODS: Individual participant data from four double-blind, randomised, placebo-controlled, acute crossover studies involving 128 cannabis users were combined for a mega-analysis. Using multilevel linear models and moderation analyses, frequency of cannabis use and schizotypal personality traits were investigated as potential moderators of the subjective, cognitive and psychotomimetic effects of acute THC. RESULTS: There was evidence of a moderating effect where increased frequency of cannabis use was associated with reduced intensity of subjective (changes in alertness and feeling stoned) and psychosis-like effects following THC when compared with placebo. Moderating effects of cannabis use frequency on acute memory impairment were weak. Trait schizotypy did not moderate the acute psychosis-like effects of THC compared with placebo. CONCLUSIONS: Our results suggest that a pattern of domain-specific tolerance develops to the acute effects of THC. Tolerance to the alertness-reducing effects occurred more readily than tolerance to psychotomimetic effects. Only partial tolerance to feeling stoned was found, and there was weak evidence for tolerance to memory impairment. Trait schizotypy did not moderate THC's effects on psychotomimetic symptoms.
Assuntos
Agonistas de Receptores de Canabinoides/farmacologia , Dronabinol/farmacologia , Tolerância a Medicamentos , Uso da Maconha , Transtorno da Personalidade Esquizotípica , Adulto , Feminino , Humanos , Masculino , Adulto JovemRESUMO
BACKGROUND: Cannabis and its main psychoactive component, Δ9-tetrahydrocannabinol (THC), can elicit transient psychotic symptoms. A key candidate biological mechanism of how THC induces psychotic symptoms is the modulation of glutamate in the brain. We sought to investigate the effects of acute THC administration on striatal glutamate levels and its relationship to the induction of psychotic symptoms. METHODS: We used proton magnetic resonance spectroscopy to measure glutamate levels in the striatum in 20 healthy participants after THC (15 mg, oral) and matched placebo administration in a randomized, double-blind, placebo-controlled design. Psychotic symptoms were measured using the Psychotomimetic States Inventory. RESULTS: We found that THC administration did not significantly change glutamate (glutamate plus glutamine relative to creatine) concentration in the striatum (p = .58; scaled Jeffreys-Zellner-Siow Bayes factor = 4.29). THC increased psychotic symptoms, but the severity of these symptoms was not correlated with striatal glutamate levels. CONCLUSIONS: These findings suggest that oral administration of 15 mg of THC does not result in altered striatal glutamate levels. Further work is needed to clarify the effects of THC on striatal glutamate.